A mining swarm is composed of many billions of tiny robots, all microscopic. Like cells in our body, they work together in groups, some will cut out pieces of ore, others move it away so more can be cut. The ore gets moved to a lift loop where it gets moved up to an orbital ring. The orbital ring is where the ore is processed, elements are removed with lasers tuned to frequencies needed to excite those and separate them from the ore. Each element is stored and used as needed. Some of it is used for construction, some stored for later use or trade. The swarm can also replicate and grow in size, but when it does this, there's less excess material for other construction or trade. Swarms on planets near a star are use stellar power (solar power), those far from a star will use fusion reactors. The swarm is usually black and very faint in visible light. The high energy nature of the process means a lot of waste heat is released, thus it is usually bright in infrared. The swarm on the surface can sometimes cover the entire surface of a planet.